{ "id": "0902.2217", "version": "v1", "published": "2009-02-12T21:03:31.000Z", "updated": "2009-02-12T21:03:31.000Z", "title": "The ring of regular functions of an algebraic monoid", "authors": [ "Lex E. Renner", "Alvaro Rittatore" ], "categories": [ "math.AG" ], "abstract": "Let M be an irreducible normal algebraic monoid with unit group G. It is known that G admits a Rosenlicht decomposition, G=G_antG_aff, where G_ant is the maximal anti-affine subgroup of G, and G_aff the maximal normal connected affine subgroup of G. In this paper we show that this decomposition extends to a decomposition M=G_antM_aff, where M_aff is the affine submonoid M_aff=\\bar{G_aff}. We then use this decomposition to calculate $\\mathcal{O}(M)$ in terms of $\\mathcal{O}(M_aff)$ and G_aff, G_ant\\subset G. In particular, we determine when M is an anti-affine monoid, that is when $\\mathcal{O}(M)=K$.", "revisions": [ { "version": "v1", "updated": "2009-02-12T21:03:31.000Z" } ], "analyses": { "subjects": [ "14L30" ], "keywords": [ "regular functions", "maximal normal connected affine subgroup", "maximal anti-affine subgroup", "irreducible normal algebraic monoid", "decomposition extends" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0902.2217R" } } }